Past Trends of Fuel Consumption and GHG
Emissions from Heavy-Duty Trucking
Joshua Linn and Yushuang Wang (Resources for the Future)
Energy Use and Policy in the U.S. Trucking Sector
October 10, 2012
Trucks are an important part of the U.S. economy
Trucking accounts for a large share of total value and
ton-miles
• Figure 1 shows shares of value and ton-miles of freight by mode
from the 2007 Commodity Flow Surveys
Trucking’s importance has been growing over time
• Figure 2 plots growth in ton-miles for the largest modes from
1997-2007
Class 7-8 combination trucks account for a growing
share of VMT and fuel consumption
• Figure 3 compares DOE estimates of VMT and fuel consumption
for single-unit class 3-8 vs. combination class 7-8 trucks
2
Figure 1: Share of value and ton-miles by mode in 2007
Share of Value by Shipment Mode
(Total = $9.5 Trillion)
Trucks (87%)
Rail (6%)
Water (1%)
Air (4%)
Pipeline (2%)
Share of Ton-Miles by Shipment
Mode (Total = 1 Trillion)
Trucks (47%)
Rail (47%)
Water (6%)
Air (<1%)
Source: 2007 Commodity Flow Survey
Note: Figures include single-mode shipments only
Figure 2: Growth in Ton-Miles (1997-2007, 1997 = 1)
1.4
1.2
1
Trucks
0.8
Rail
0.6
Water
0.4
Air
0.2
0
1996
1998
2000
2002
2004
2006
2008
Figure 3: VMT and Fuel Consumption by Truck Type
VMT (Millions Miles)
160,000
140,000
120,000
100,000
80,000
60,000
40,000
20,000
0
1970
Fuel Consumption (Millions Gallons)
30,000
25,000
20,000
15,000
10,000
5,000
1980
Single-Unit (Class 3-8)
1990
2000
2010
Combination (Class 7-8)
0
1970
1980
Single-Unit (Class 3-8)
1990
2000
2010
Combination (Class 7-8)
Source: Transportation Energy Data Book
Contribution of heavy-duty trucks to GHG emissions
Figure 4: medium and heavy duty trucks account for large
share of GHG emissions
Table 1: GHG emissions by transportation mode
• Emissions from trucking have been growing more rapidly than
other modes
Figure 5: Diesel and gasoline consumption over time
• Diesel fuel consumption has been growing more quickly than
gasoline consumption
• High correlation between consumption and GDP
Figure 4: GHG emissions by travel model
Table 1: GHG Emissions (million metric tonnes CO2eq)
1990
2000
2009
Percent Change
Trucks
231.1
354.5
365.6
58.2
Freight rail
34.5
42.8
37.2
7.8
Ships and other
boats
30.6
48.3
13.5
-55.9
Freight total
356.0
510.5
467.9
31.4
1,145.7
1,391.8
1,326.1
15.7
23.0
26.4
25.8
12.2
Passenger total
Freight as % total
transportation
Source: FHWA, Freight Facts and Figures 2011
Figure 5: Fuel Consumption, GDP, and Fuel Prices
5
4
3.5
4.5
3
4
2.5
3.5
2
1.5
3
1
2.5
0.5
2
0
1970
1975
1980
1985
1990
1995
2000
2005
Log Gasoline Consumption
Log Diesel Consumption
Diesel Price (2005 $/gal)
Log GDP
2010
Sources: EIA State Energy Data System (Consumption and Fuel Price); BEA
(GDP); BLS (CPI)
Accounting for the increasing GHG emissions
VMT and ton-miles have been increasing steadily
• 30 percent increase 1997-2007 (Figure 2)
Payload-specific fuel consumption (gallons per ton-mile)
has decreased dramatically (Figure 6)
• PSFC has decreased much more for heavy-duty trucks than for
passenger cars or light trucks
• But not as quickly as ton-miles have increased
Figure 6: Payload specific fuel consumption by vehicle type
Heavy-duty trucks
Source: NAS (2010)
Source: EPA (2012)
Passenger cars and light trucks
0.045
0.04
0.035
0.03
0.025
0.02
0.015
0.01
0.005
0
1975
1980
1985
Cars
1990
1995
2000
Light Trucks
2005
What could be behind the changes in GHG emissions?
Greater demand for trucking services
• Is demand proportional to economic activity?
Mode shifting
• Do fuel prices, regional trends in economic activity, or
other factors affect choice of rail, air, or truck?
Innovation and technology adoption
• Are carriers using better technology? Fuel prices,
industry structure, or something else?
Changing utilization patterns
• More efficient networks, e.g., hub-and-spoke and GPS?
VIUS: a deeper look at utilization and fuel consumption
Focus on class 8 tractors in 1982, 1992, 2002
Compare distributions of age, GVWR, VMT, ton-miles, and
gallons per ton-mile over time
Comparing 1982 and 2002, the average truck:
• Is slightly newer and considerably larger
• Travels 10% more miles
• Carries 15 % more ton-miles
• Has 13% lower payload-specific fuel consumption
Source: VIUS, authors’ calculations
Figure 7: Age for Class 8 Commercial Trucks
Source: VIUS, authors’ calculations
Figure 8: GVWR for Class 8 Commercial Trucks
Source: VIUS, authors’ calculations
Figure 9: VMT
Source: VIUS, authors’ calculations
Figure 10: Ton-Miles
Source: VIUS, authors’ calculations
Figure 11: Gallons per Ton-Mile
Source: VIUS, authors’ calculations
Summary and questions
Trucking plays a very important role in the economy, and fuel
consumption and GHG emissions have been increasing
Greater ton-miles has been partially offset by lower payload
specific fuel consumption
What is driving these trends?
• What are the main factors behind trucking demand?
• Why do carriers adopt better technology or change their
utilization patterns?